There is no such thing as a can't miss NFL prospect when it comes to QB's. For everyone that translates from the collegiate game there are two that do not.
While I think it would be insane for Carolina to forego the opportunity to get a potential franchise QB even with less than 50% odds, it would be even more insane than to dismiss signing Orton who has proven he can be a VERY GOOD NFL QB in the right system. Like 500 yards single game passing and leading the lead in efficiency for almost half the season good.
One is a proven- albeit older- commodity. The other is nothing more than Joey Harrington, Todd Marinavich, Jeff George, Alex Smith, JaMarcus Russell, Ryan Leaf, etc (could list a hundred, really) at this point...